What the heck IS this thing?

[BFG]

I'm starting to think this has to do with a larger issue in my game.  I believe the units are supposed to be Locusts of Chiron, given the way they behave (and the sound they make when I blow them up ).
In the same game, I've noticed probe teams that look like Battle Ogres, and Isles of the Deep that look like those green snake things whose name escapes me right now.  In another thread, Yitzi and others confirmed this as a graphics bug present when the Scenario Editor is used in SMAX.

[Buster's Uncle]

I've spontaneously had the city-thing show up a few times in normal games.  You've definitely got a broken game.

[BFG]

I've spontaneously had the city-thing show up a few times in normal games.  You've definitely got a broken game.

Oddly, everything seems fine when I don't use the scenario editor.
Any pattern to when those units appear in your game?  Is it usually after significant ecodamage?  And what kind of stats/names do they have?

[Buster's Uncle]

I couldn't say - it's happened maybe twice, three times, all years ago.